1. Field of the Invention
The present invention relates to a direct current (DC) motor, and in particular to a manually operated brushless DC motor that is used mainly for instruction and demonstration.
2. The Prior Arts
In general, motors work by the interactions between magnetism and electric currents. A DC motor is capable of making high-speed rotation. It is achieved by using brushes and a commutator to synchronize the rotation speed of a rotor with the rate that a current changes its direction, so that the magnetic force generated by the current keeps driving the rotor of the motor in the same direction.
Because of the high-speed rotation, schools and institutions are unable to provide a low-speed motor or a generator to students for viewing its motion clearly and a hand-on learning. Conventional devices for demonstrating electric machines still keep the brushes. Therefore, the problem mentioned above has not been solved.